Accompanying the progress of technology and the change of business modes, the use of plastic money such as credit card as a method of payment is becoming more popular. A card holder does not have to carry cash with them, facilitating the convenience of consumer transactions. Plastic money therefore replaces cash transactions, and becomes the main stream business transaction method.
The conventional card paying mechanism is shown in FIG. 1. A reading unit A11 in a magnetic card reader A1 is used to read data in a card holder's credit card, and the analog data is converted to digital data through an analog/digital converting chip A12 in the magnetic card reader A1. Finally, the digital data is transmitted to a transaction terminal A2, and this transaction can then be confirmed after the data in the credit card is verified.
Detailed block diagrams for a conventional magnetic card and a conventional transaction terminal are shown in FIG. 8. When a magnetic head B11 of a magnetic card reader B1 reads a magnetic card signal from sensing units B11a/B11b/B11c of a magnetic head B11, decode circuits B122a/B122b/B122c of a converting chip B12 start to decode the magnetic card signal and the decoded (0, 1) data will be transmitted through STROBE signal lines (STROBE1, 2, 3) and DATA signal lines (DATA1, 2 &3). Each pulse on the STROBE signal lines indicates an effective bit data transmitted on the DATA signal lines. Three signal lines Card Load 1, Card Load 2 and Card Load 3 are connected to an AND gate (wired-AND). As long as any of the signal lines Card Load 1, Card Load 2 and Card Load 3 has a signal transmitted thereon, the whole set of wired-AND signal lines Card Load 1, Card Load 2 and Card Load 3 are activated to notice a main controller B21 of the transaction terminal B2 through a first connector B13 and a terminal connector B22 of the transaction terminal B2, that a magnetic card signal is coming in. Note that the first connector B13 of the magnetic card reader B1 and the terminal connector B22 of the transaction terminal B2 are compatible in signal transmission. Also the decoded magnetic card signals are only sent through the terminal connector B22 to the main controller B12 in an “unidirectional” manner. Afterwards, the main controller B21 starts to receive the magnetic card information transmitted via the magnetic card signals. However, there are some shortcomings regarding the conventional transaction mechanism mentioned above. (1) The signals transmitted through the STROBE and Data signal lines of the converting chip B12 are all output only (unidirectional); namely, bidirectional communications between the magnetic card reader B1 and the main controller B21 of the transaction terminal B2 are not allowed. (2) As soon as the main controller B21 of the transaction terminal B2 detects that a signal on the Card Load signal lines is activated, the main controller B21 must be ready immediately to receive the coming magnetic card information. If in any circumstances the main controller B21 of the transaction terminal B2 misses any pulse sent on the STROBE signal line, that means there is a bit data on the DATA signal line sent already but not received by the main controller B21.
Furthermore, after new identification technologies such as non-contact card reader (e.g. Radio Frequency Identification [RFID] or Near Field Communication [NFC] card reader) and smart card reader become more popular, those new non-magnetic card readers and the conventional magnetic card reader exist together in the market in parallel. However, the interfaces and transmission protocols of those new non-magnetic card readers have compatible issues with the conventional magnetic card reader and the conventional transaction terminal. The retailers usually need to make some hardware and/or software adjustments (such as upgrade or replacement) so that their transaction terminals can be compatible with both the conventional magnetic card reader and the new non-magnetic card readers. For example, in FIG. 1, a main controller (not shown) of the conventional transaction terminal A2 can only receive the signals from the magnetic card reader A1 in an unidirectional manner, which is not sufficient for the bidirectional-transmission requirements of the new non-magnetic card reader. Therefore, such transaction terminal usually needs a large scale of hardware upgrades. On the other hand, for those transaction terminals with main controllers capable of receiving the signals of the magnetic card reader A1 and give commands in a bidirectional manner, it is easier to connect with the new non-magnetic card readers, but still difficult connecting with both the conventional magnetic card reader and the new non-magnetic card readers without any hardware change.
Purchasing is not limited to a local area due to the popularity of no-shop sales; people can make purchases even if they are in a vehicle. However a consumer must take out a credit card and insert it in a card reader in order to make such a transaction while in a vehicle, which is very inconvenient for a consumer. The transaction process is complex and tedious to the extent of decreasing consumer purchase interest. In the meantime, the compatible issues between the conventional magnetic card reader and the new non-magnetic card reader are critical for the users.